<!DOCTYPE html>
<html lang="zh-CN">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    div {
      width: 200px;
      height: 200px;
      background-color: skyblue;
    }

    span {
      background-color: orange;
    }
  </style>
</head>

<body>
  <!-- 块级元素排版规则： -->
  <!-- 从上往下、垂直布局、独占一行 -->
  <div>我是第1个div</div>
  <div>我是第2个div</div>
  <div>我是第3个div</div>

  <!-- 行内元素或行内块元素的排版规则： -->
  <!-- 从左往右、水平布局、空间不够自动折行 -->
  <span>我是span标签</span>
  <span>我是span标签</span>
  <span>我是span标签</span>
  <span>我是span标签</span>
  <span>我是span标签</span>
  <span>我是span标签</span>
  <span>我是span标签</span>
  <span>我是span标签</span>
  <span>我是span标签</span>
  <span>我是span标签</span>

</body>

</html>